MATLAB Data Types and Structures 3

Question 1

What happens when you concatenate a `double` array and a `single` array using `[]` in MATLAB?

Accepted Answer

The result is single

Answer

When concatenating single and double arrays, MATLAB converts the result to single (lower precision wins to save memory).

Question 2

How do you add a new field `age` to an existing struct `s`?

Accepted Answer

s.age = 30

Answer

Simply assigning `s.age = 30` dynamically adds the field `age` to the struct.

Question 3

What does `fieldnames(s)` return for a struct `s` with fields `x` and `y`?

Accepted Answer

{'x';'y'}

Answer

`fieldnames()` returns a cell array of character vectors containing the field names.

Question 4

Which statement correctly creates an empty cell array of size 3x2 in MATLAB?

Accepted Answer

C = cell(3,2)

Answer

The `cell(m,n)` function creates an m-by-n cell array where every cell contains an empty matrix.

Question 5

What is the purpose of `int8` versus `uint8` in MATLAB?

Accepted Answer

int8 stores signed integers (-128 to 127); uint8 stores unsigned integers (0 to 255)

Answer

`int8` represents signed 8-bit integers (-128 to 127), while `uint8` represents unsigned 8-bit integers (0 to 255).

MATLAB - MATLAB Technical Computing Practice Test